- // Scavenging this update frame as normal would be disastrous;
- // the updatee would end up pointing to the value. So we turn
- // the indirection into an IND_PERM, so that evacuate will
- // copy the indirection into the old generation instead of
- // discarding it.
+ // So, if the frame points to an indirection, it will get
+ // shorted out when we evacuate. If this happens, we have no
+ // closure to update any more. In the past we solved this by
+ // replacing the IND with an IND_PERM, but a better solution
+ // is to replace the update frame with a frame that no longer
+ // does the update and just uses the value already computed by
+ // the other thread, so that is what we now do.